Purified forms of glucosyltransferase (GTF) have been found previously to be effective in immunizing animals against dental caries. The purified GTF typically may be employed in a vaccine, which vaccine is administered orally or into or near the oral cavity of a patient susceptible to dental caries, to provide for immunization of the patient against dental caries (see, for example, U.S. Pat. No. 4,150,116, issued Apr. 17, 1979).
GTF has been prepared by a method in which it is derived from the culturing of Streptococcus mutans in the presence of glucose and dialyzable nutrients, to form a mixture of culture cells and a supernatant containing the GTF. The supernatant is subsequently incubated with a sucrose which is synthesized slowly in situ to a water-insoluble polysaccharide. The GTF is recovered from the bound, water-insoluble polysaccharide by the employment of a denaturing solvent, to break the bond between the polysaccharide and the GTF enzyme, and the GTF enzyme is recovered and is subsequently concentrated in purified form by gel filtration (see, for example, U.S. Pat. No. 4,250,262, issued Feb. 10, 1981).
The method of preparing GTF as described, while suitable for the preparation of small laboratory or test amounts of GTF, is not wholly suitable for the production of GTF for pilot or commercial use, wherein the time of preparation, the efficiency of reaction and the recovery of materials are desirable, in order to provide for an effective cost-efficient process. Furthermore, the eluted GTF contains a large amount of soluble glucan which must be removed by gel filtration.